1. Technical Field
The present invention relates to a method and apparatus for performing a plasma process on particles and, more particularly, to a plasma processing method and apparatus of a plasma process such as dry etching suitable for manufacture of a semiconductor device such as a semiconductor integrated circuit device in which semiconductor elements are formed on a very small particle such as a spherical semiconductor.
2. Description of the Related Art
In an ordinary single semiconductor device or a semiconductor device such as a semiconductor integrated circuit and the like, a semiconductor device or a semiconductor integrated circuit is formed on a plate-shaped semiconductor wafer or semiconductor chip. In the case of the configuration, however, high costs of the semiconductor device and a fabrication line are an issue.
On the other hand, recently, as shown in FIG. 5, in place of the plate-shaped semiconductor wafer or semiconductor chip, a technique of configuring a semiconductor integrated circuit on which semiconductor devices 32 are formed on the surface of a spherical semiconductor 31 that is a silicon single crystal has been proposed.
This has been achieved since there is an advantage that the surface area to the volume of the semiconductor is larger as compared with the plate-shaped semiconductor device and the spherical semiconductor chip is easier to mount on a wiring board or the like.
In the case of fabricating a semiconductor device by using such a spherical semiconductor, a processing step such as etching and the like is necessary. It is requested to smoothly perform the process such as etching on almost the whole surface of the spherical semiconductor without continuous stop in order to raise the throughput and without any contact with other things so as not to cause scratches and a mechanical damage which deteriorates the yield.
It is an object of the invention to provide a method and apparatus for performing a plasma process on particles, capable of certainly performing a plasma process especially such as isotropic plasma etching and the like on the whole or entire surface of a particle.
According to the method of the invention, a plasma process is performed on particles by passing the particles through a passage in which an inductive coupled plasma is generated.
According to the invention, an apparatus for performing a plasma process on particles comprises a passage of particles and plasma generating means for generating an inductive coupled plasma in the passage and performs the plasma process on the particles by passing the particles through the plasma.
As described above, in the plasma processing method according to the invention, the particles as members to be subjected to the plasma process are passed through a plasma, especially, an inductive coupled plasma, that is, a plasma in which activated species activated by a sufficiently large amount of energy exist at high density. Consequently, the plasma process can be certainly performed almost on the entire surface of the particle during the passage.
The plasma processing apparatus according to the invention generates a standing wave plasma by simply passing a current to a coil and therefore can perform an efficient plasma process.